Thermostatic control



Oct. 25, 1932. w MCKEE 1,884,794

THERMOSTATIC CONTROL Filed Aus. 4. 1930 Patented ,Octf 25, 1932 UNITED. STA-TES PATENT 4oI-FICE GARNET W. MCKEE, F ROCKI'ORID, ILLINOIS THERMOSTATIC CONTROL .irai-1 I Application l'd August 4, 1930. Serial No. 472,836.

rI he present invention relates to improvements 1n thermostatic controls, and has partlcular reference to a novel control device for controlling the iiow of gas to a burner for awater heater in accordance with the temperature of the water.

If hard water is heated to a temperature above150 F., an excessive amount of lime will be deposited in the water lines; One of l0 the objects of the present invention therefore A further object resides -in the provisionl of a novel thermostatic control device which is simple, compact 'and inexpensive'in .construction, and in which the lpperativelparts are sealed out of contact with the water.

Other objects and advantages will become apparent "as the description proceeds. Referring more particularlygt'o the drawing, Figure l is a bottom -view of a thermo' static control'device embodying the Afeatures Aof my invention.

Fig. 2 is a fragmentary side view, partially sectioned in a vertical of Fig. l.

. u Fig. 3' is aside elevational view of a modi# tied form of the invention.

Fig. 4 is a vertical sectional View taken along lineifllo'f Fig. 3. While the inventiQn is susceptible of various'modilcations and alternative constructions, I have shown in the drawing and will herein describe in detail the preferred embodiment, but it is to be understood that I do not thereby intend 'to limit the invention to' the specific form disclosed, but intend .to cover' all modifications and alternativecolb. structions fall-ing within the spirit and scope of the invention as expressed in the appended l.

claims.

planey along line 2 2 Figs. l and 2 comprises a-suitable-base 5 preferably in the formofa plate. lA cover 6 .is removably secured on the base 5, and,

constitutes therewith a casing, the interior of which defines a valve chamber 7. Formed on the underside of the base 5 are `two tubular enlargements defining Vfluid passages 8 and 9 opening in spaced relation through the base into the chamber 7. Of the passages 8 and 9, one is the inlet passage adapted to be connected to a suitable source of fluid supply (not shown), and the other is the discharge passage adapted to 'be connected to a burnersu'pply line (not shown).

A valve member 10 is mounted to seat over one ofthe passages, foi` example the passage 9. It will be understood that the valve may be utilized to cont-rol the fuel mixture, or eitherl of its constituents, namely fuel gas or air. Whilel the invention is particularly inztended to controlv the supply of fuel mixture to a burner (not shown) for a water heater (not shown) in accordance with the temperature of the'wat'er, and is herein described 75 1n -its adaptation to such use,it will be evident that the invention in various. of its aspects is .not llmited to such use, but may beutilized to control the iow of any fluid in accordance with predetermined 'temperature conditions., 0

The valve member l0 is responsive to a suitable pressurestat.v In the present instance, the pressurestat comprises a'tube 11 closed and tapered at one end. The other-'lend of v the tube 1l is sealed with a pressure respon- 85. sive member, such asa diaphragm 12. Prefl erably,the peripheral margin of the.4 diaphragm 12 is disposed againsta shoulder 13,A and is secured inplac'e byv a ring 14 soldered to the tube 11.

The tube 11 is formed intermediate its ends with external threads 15 adapted to be threaded into one wallofthe water chamber (not shown) with the tapered end in contact with 'the water. Preferably, the other end 95 of the tube 11 is formed with an annular on the underside of the base 10, and serving to Referring moreparticularly to the draw-- ing, the thermostatic control device 'shown in clamp the ring 14 securely against the end of into the recess 18, andthe paraiin 13 is introduced through an opening in the tip of the tube. W'hen the tube 11 is lilled'with solid paratlin, the opening 20 is closed by means of a screw plug 21. It will be evident that the paraiiin upon melting will flex the diaphragm 12 outwardly, and upon solidify-v ing will permit the diaphragm to return to its innermost position.

Extending slidably through a bore 22 in the boss-17 from the recess 13 into the chamber 7 is a plunger 23. The end of the plunger 23 inthe recess 18 is provided withvan enlarged head 24 resting on the diaphragm 12.

,Pivotally mounted intermediate its ends in a bracket 25 on the base 5 is a'lever 26 one arm 27 of which carries an adjustable set screw 28 engaging the end of the plunger 23 in the cham er 7.

A coiled compression spring 29 interposed between the base 5 andthe other arm 30 of the lever tends to maintain the screw 28 in contact with the plunger 23 and the latter in contact with thediaphragm 12. Preferably,

one end of the spring 29has a plurality of tight coils 31 threaded onto a screw 32 carried by the arm 30. Thus, the spring 29 is ield in place on the arm 30, and cannot work oose.

The free end of the arm of the lever 26 carries the valve member 10. Preferably screws 33 and 34 are provided respectivel on the arm 30 and the valve member 10. X coiled spring 35 is provided with a plurality of tight coils 36 and 37 on its opposite ends threaded respectively onto the screws 33 and 34 to secure the valve member 10 yieldingly to the arm 30. Thus, the valve member 10 is adapted to be seated with a balanced pressure. The pressure may be varied by adjusting the set screw 28 to adjust the extent of movement of the valve member 10 between open and closed positions.

In operation, when the temperature eX- ceeds 144 F., the paraiiin 19 will melt and expand against the diaphragm 12. The movement of the diaphragm 12 is imparted through the plunger 23, the lever 26 and the spring 35 to the valve member 10 to close the passage 9. The valve member 10 seats squarely with a balanced pressure. When the temperature drops below 144 F., the paraffin 19 will solidify, whereupon the spring 29 will cause the valve member 1() to open.

Referring now to Figs. 3 and 4, the modi ied form of the invention comprises a valve casing 38 formed with inlet and discharge passages 39 and 40 and with a valve seat 41 intermediate said passages. A valve member 42 is mounted for movement into and out of engagement with the valve seat 4l.

Mounted in one side of the casing 38 is an elongated sleeve 43 which is formed intermediate its ends with threads 44 adapted to be threaded into one wall of the Water chamber (not shown). Secured to the fre-e end of the sleeve 43 is a tube 45, with a diaphragm 46 interposed between the connecting ends of the sleeve and the tube. The tube is tapered, and is filled with paraiiin 47 which is introduced through an opening 48 in the free end normally closed by a screw plug 49.

In the present instance, a direct acting connection is provided betweeen the valve member 42 and the diaphragm 46. This connection comprises a plunger 5() reciprocable in the sleeve 43, with one end supporting the valve member 42 and the other end bearing against the diaphragm. A coiled spring 51 encircling the plunger 50, and abutting at its ends against an inner peripheral flange 52 in the sleeve 43 and a peripheral flange 53 onthe plunger tends to urge the latter against the diaphragm 46 and the valve .member 42 away fromy the seat 41.

A yieldable connection is provided between the valve member 42 and the plunger 50. To this end, the valve member 42 is formed in one side with an axial bore 54 slidablyfrecei'ving the adjacent end of the plunger 50. A bolt 55 extends through the valve member'42 into adjustable threaded engagement with the end of the plunger 50,.and has a head 56 limiting the outward movement of the valve member. A coiled spring 57 encircling the plunger 50 and abutting at its ends against the valve member and a peripheral shoulder 58 on the plunger tends to move the valve member outwardly against the head 56.

The plunger 50 is formed with a diametrical bore 59 adapted for the temporary reception of a pin (not shown) for holding the plunger away the latter is being solder-ed in place against the shoulder formed for the purpose in the tube 45. After soldering the diaphragm 46 'securely in place, the described pin isy removed and the spring 51 then forces the plunger 50 against the diaphragm 46 when introducing the paraiiin- 47 to the tube.

I claim as my invention 1. A control device comprising, in combi nation, a passage, a valve controllingy said passage, a closed tapered member having a flexible Wall at its large end, paraffin completely filling said member and sealed there-4 in, said wall being responsive to changes in volume of said paraffin, andaneans operatively conneetlng said wallto said valve.

from the diaphragm46 while 2. In a control device, in combination, a, casing defining a valve passage, a valve actuatoi` mounted 1n said casing, a valve for controlling said passage, said actuator and said valve being provided respectively with oppositely disposed screws, and an open coiled connecting spring having a .plurality of tight coils on each end threaded respectively onto said screws.

3. In a control device, in combination, a casing defining a valve passage, a valve actuator mounted in said casing, a valve for con trolling said passage, said actuator being provided With a 'fixed screw, and an open coiled spring connected to said valve and having a plurality of tight coils on one end threaded onto said screw.-

4. A control device comprising, in combination, a casing formed with a passage, a. valve for controlling said passage, a hollow conical member having a yieldable wall closing its large end and secured at said end to said casing, the small end of said member being free, wax completely filling said member and sealed therein, and means for transmitting the movements of said wall to said valve.

5. A control device comprising, in combination, a casing having a passage, a valve'for controlling said passage, a hollow member having a chamber of gradually decreasing cross-sectional area and having a yieldable Wall closing the large end of said chamber, said member being secured to said casing, a substance adapted to undergo a changel in volume upon being subjected to varying temperatures, said substance being sealed in said member, and means for transmitting the movements of said Wall to said valve.

6. A control device comprising, in combination, a casing having a passage, a valve for controlling said passage, a conical tube having a flexible Wall closing its large end and secured at its large end of said casing, the small end of said tube being free, wax sealed within said tube, and means for transmitting the movements of said wall to said valve, said means including spring means tending to cause said wall to follow any reduction in volume of said wax.

7 A control device comprising, in combination, a valve casing formed with a passage, a valve for controlling said passage, an elon- -the large inner end of said tube, a plunger slidable longitudinally in said sleeve and bearing at one end against said Wall, and means operatively connecting the other end of said plunger to said valve.

In testimony whereof, I have l .reunto affixed my signature. c

GARNET W. MCKEE.

gated sleeve rigid with said casing, a conical tube with its large end threaded onto the free end of said sleeve, a. flexible diaphragm secured between said tube and the free end of said sleeve and constituting a wall closing the large inner end of said tube, the small outer end of said tube being free, wax adapted to undergo a change in state with an attendant change in volume at a predetermined temperature, said vWax filling and being sealed in said tube, and means for transmitting the movements of said wall to said valve. 

